English:Thracians or Thracian Bulgarians (Bulgarian: Тракийски българи or Тракийци) is a regional, ethnographic group of ethnic Bulgarians, inhabiting or originating from Thrace. Today, the larger part of this population is concentrated in Northern Thrace, but much is spread across the whole of Bulgaria and the diaspora. Until the beginning of the twentieth century the Thracian Bulgarians lived also in the whole of Thrace, then part of the Ottoman Empire. After the persecutions during the Preobrazhenie Uprising and the ethnic cleansing, caused to the Bulgarian population in Eastern Thrace after the Second Balkan War, this people were expelled from the above area. After the World War I Bulgaria was required to cede Western Thrace to Greece. A whole population of Bulgarians in Western Thrace, was expelled into Bulgaria-controlled Northern Thrace. This was followed by a further population exchange which radically changed the demographics of the region toward increased ethnic homogenization within the territories each respective country ultimately was awarded. The last flow of Thracian refugees into Bulgaria was as the Bulgarian Army pulled out of the Serres-Drame region in late 1944.)